A two-dimensional type I superionic conductor

Superionic conductors possess liquid-like ionic diffusivity in the solid state, finding wide applicability from electrolytes in energy storage to materials for thermoelectric energy conversion. Type I superionic conductors (for example, AgI, Ag2Se and so on) are defined by a first-order transition to the superionic state and have so far been found exclusively in three-dimensional crystal structures. Here, we reveal a two-dimensional type I superionic conductor, α-KAg3Se2, by scattering techniques and complementary simulations. Quasi-elastic neutron scattering and ab initio molecular dynamics simulations confirm that the superionic Ag+ ions are confined to subnanometre sheets, with the simulated local structure validated by experimental X-ray powder pair-distribution-function analysis. Finally, we demonstrate that the phase transition temperature can be controlled by chemical substitution of the alkali metal ions that compose the immobile charge-balancing layers. Our work thus extends the known classes of superionic conductors and will facilitate the design of new materials with tailored ionic conductivities and phase transitions

Professor Barrie Vernon-Roberts, AO, MD, BSc, PhD, FRCPath, FRCPA, FAOrthA (Hon), FRS.SA

This issue of Inflammopharmacology contains papers that have been submitted to commemorate the life and work of Professor Barrie Vernon-Roberts, an outstanding clinical scientist in the field of bone pathology and its pharmacological regulation. This review briefly summarizes his major works and achievements as well as a list of his publications.K. D. Rainsford, D. R. Hayne